8.2 命令行参数示例（实验）
public class Test {
public static void main(String[] args){
if(args.length==0){
System.out.println("you don't set command line parameters!");
}else{
for (int i=0; i
System.out.println("args[" + i + "] is: " + args[i]);
}
}
}
}
when use eclipse, don't "run as application",directly use "run configurations/run", then add in aguments in program arguments.（当运行eclipse，不要"run as application"，而直接用"run configurations/run"，然后加上参数在，program arguments.）
